The present invention generally relates to tufting machines, and it is specifically directed to a tufting machine that has a tufting head comprised of distinct yarn-inserting and yarn-catching/cutting elements that are independently movable relative to each other in order to facilitate the production of artificial athletic turf bearing multi-colored graphic designs.
Many of the aspects and features of machines for manufacturing tufted products have evolved considerably over the years. Conventional broadloom tufting machines have been designed to enable the manufacture of carpet and artificial athletic turf in high volume. Such high output tufting machines typically feature a backing feed mechanism comprising an arrangement of feed and take-up rollers that feed an elongate sheet of backing fabric past a tufting head. The tufting head portion of the machine generally features one or more elongate needle bars having hundreds of aligned tufting needles which are disposed above the backing sheet, as well as an equivalent plurality of loopers that are disposed below the backing. Each needle bar carries a row of aligned needles that each receive yarn, via any of a variety of suitable yarn feed mechanisms, from a corresponding spool situated within a yarn creel. As the backing sheet is conveyed past the tufting head, the needles are continually reciprocated downward to penetrate and insert yarn into the backing sheet. The loopers operate in synchronicity with the needles so that as each needle momentarily protrudes the backing, a corresponding looper catches its yarn before the needle returns upward. This cooperative needle and looper action produces “loop pile” tufts of yarn in the backing. Additionally, knives can be used to sever each of the just-formed loops to render “cut pile” tufts.
Where uniformly patterned carpet or vast monochrome sections of athletic turf are to be produced, the needle bar of the type of broadloom tufting machine used may span the entire transverse width of the backing material. Thus, the tufting needles along the needle bar generally remain stationed at constant axial positions (i.e., the needle bar does not shift laterally with respect to the backing). The incremental, longitudinal progression of the backing material that follows each stroke of the needle bar causes the laterally-aligned needles to form successive lateral rows of tufts. However, while broadloom tufting machines that employ single axis needle bar movement may be preferable for high output production of tufted products of uniform tuft placement and yarn color, they are not ideal for tufting multicolored designs. For creating multicolored tuft patterns in backing materials, such as may be necessary when manufacturing the logo-bearing sections of artificial athletic turf, tufting machines have been improved to enable their needle bars to shift laterally, relative to the backing, in order that the particular type of yarn delivered by particular individual needles be selectively inserted into the backing at specific tuft locations in accordance with a preconceived pattern. For example, U.S. Pat. No. 4,829,917 to Morgante, et al. discloses the use of a computer-controlled hydraulic actuator for shifting the needle bar of a tufting machine into different lateral positions in response to pre-selected stitch pattern information stored in the computer. As another example, U.S. Pat. No. 5,979,344 to Christman, Jr. discloses the use of computer-controlled inverse roller screw actuators for shifting needle bars laterally, as well as for shifting the backing sheet itself laterally, in order to tuft a graphic pattern of yarn into the backing as it advances longitudinally past transversely aligned needles.
However, conventional tufting machines that employ backing feed mechanisms are not optimum for producing highly detailed color images, such as some artistic logo-bearing sections of artificial athletic turf, even if their tufting heads are laterally shiftable. For one, their tufting heads generally perform needle reciprocation and shift in timed relationship with the stepped longitudinal progression of the backing fabric that is being fed through the machine. Whenever that motion relationship is altered, as may occur unintentionally for a variety of reasons, the tufting needles may fail to insert yarn tufts at the precise positions necessary to produce the desired image effect. For example, if the backing feed mechanism experiences any lag or surge in its operation, that will likely create inconsistency in the longitudinal spacing between adjacent rows of tufts which, in turn, could distort the overall graphic image being tufted.
Furthermore, athletic field logos, for example, are often broader than the tufting zones of conventional machines—which are typically up to 15 feet wide. Therefore, graphic logos often must be manufactured in separate sections. The sections are individually tufted and then glued, side-by-side, onto a base layer material to form the whole image. However, using a conventional tufting machine with a backing feed mechanism to tuft the various adjacent sections of backing separately can be problematic, not only because the machine may experience operating irregularities in the cooperative motions of its tufting head and backing feed mechanism, but also due to inherent characteristics of the backing material itself. To with, backing sheets are typically fabricated of coarsely woven material that may be stretched nonuniformly or skewed as they are advanced by the backing feed mechanism. Consequently, there exists the potential for one image-bearing section of backing to progress through the tufting zone differently, in some respect, than does an adjacent section, and that may render color discontinuity within the assembled tufted image.
To address this issue, tufting machines have been developed to enable the tufting head component of the machine to advance multi-directionally and along perpendicular axes in order to tuft a pattern into a fixedly held backing piece. U.S. Pat. No. 5,743,200 to Miller, et al. discloses such an apparatus for manufacturing tufted rugs. Resembling the construction of the machine of the present invention, the Miller tufting machine employs a gantry component which carries a tufting head adapted to move along an X-axis (i.e., lateral relative to the backing), while the gantry is movable along a Y-axis (i.e., longitudinal relative to the backing). The Miller tufting head is disposed above the backing material, and it is mounted to the gantry via its attachment to a frame which is gearably connected to and movable along the gantry. The tufting head generally comprises a cylinder that is slidably secured to the frame, a piston that reciprocates within the cylinder, a needle that is secured to the bottom end of the cylinder and a blade that is positioned within the needle and is secured to the bottom of the piston. The blade projects from and retracts into the needle to assist the needle in protruding down through the backing to form loop pile tufts therein. The Miller tufting machine also includes a second, lower gantry that is disposed below the backing material and moves along a Y-axis in synchronicity with the upper gantry. This lower gantry provides underlying support for the backing material in order to limit the downward deflection that would otherwise result from the pressure applied by the blade and needle operating on the backing.
Nevertheless, it can be appreciated that there is an outstanding need for a tufting machine that has a configuration which is similar in that it includes a computer controlled tufting head adapted to move along both X and Y axes and entirely about a statically held backing piece upon which it operates in order to insert various yarns into the backing at precise locations in accordance with a design pattern stored in the computer, but that includes an improved tufting head configuration for producing athletic turf products of precise graphic design. More specifically, there is a need for such a machine to employ a tufting head that is defined by two distinct and asynchronously driven parts which constitute: (a) a needle carriage which is oriented above a statically held sheet of backing material being tufted and comprises a number of individually controlled needles that are each threaded with a separate color of yarn and are selectively reciprocated along a Z-axis to insert those yarns into the backing material as the carriage journeys along an X-axis; and (b) a looper carriage which is oriented below the backing and is not mechanically connected to the needle carriage, but rather is selectively advanced and retracted, along a parallel axis, in order for its looping element to catch and its cutting element to cut the yarn being injected through the backing by the particular needle carriage needle in tufting action. Furthermore, there is a need for the looper carriage to include a fewer number of looping and cutting parts than the quantity of needles disposed within the needle carriage and for the looper carriage to, therefore, be able to shift to and fro in non-unison with the needle carriage so that a single looper and cutter pair may selectively cooperate with each one of multiple needles. Such a tufting head configuration lends itself to avoiding an issue of the minimum needle gauge achievable (i.e., the minimum spacing required between adjacent needles) being dictated by how closely adjacent looper and knife pairs can be disposed within a looper carriage of a type that features a separate looper and knife pairing for cooperation with each needle disposed in the needle carriage. The tufting machine of the present invention substantially fulfills these outstanding needs.